UC Davis police begin criminal probe into explosion

Several dozen UC Davis campus residents evacuated by authorities Thursday were allowed back into their homes Friday, and university police say they are launching a criminal probe into the explosion which caused the ruckus.

UCD Police Chief Matt Carmichael still won't disclose the name of the researcher who kept a stash of dangerous chemicals in his Russell Park apartment. The discovery came after a late-night visit to Sutter Davis Hospital by the man, who had apparently injured his hand in a small explosion while tinkering in his home laboratory. Hospital staff called police at around 1:30 a.m. Thursday, prompting them to investigate the apartment.

Nor will authorities say what chemicals, or in what quantity, the man was keeping there -- although it took several bomb squads 20 hours and eight controlled detonations to remove them all safely.

"I can tell you this," said Carmichael in a phone interview. "We had several bomb teams assisting us including the ATF, FBI, Yolo County bomb team, Sacramento County bomb team, CHP. And based on our initial assessment ... it was determined that the best course of action would be to slowly and methodically and safely remove what known and unknown chemicals were there."

In the case of some of the chemicals, authorities decided it "would not be safe or prudent to move them very far," Carmichael said. So they took over a nearby clearing, alerted neighbors that there would be some loud noises, and detonated the materials on site.

That led to a series of eight "explosion sounds" Thursday night, Carmichael said, with the last one occurring close to midnight.

Residents were given the green light to move back in at about 1:30 a.m. Friday, although many had already secured other housing for the night, he said. A total of 40 units had been evacuated, most of them fourplexes.

"We're thinking the number was about 74 people that were displaced," including some children, Carmichael said. Associated Students and other groups helped provide overnight housing and meals for the evacuated residents.

"We asked them to leave on pretty short notice" the night before, he said.

As for the researcher and the criminal investigation, "For right now I'm going to (be) very tight-lipped," Carmichael said.

"He was what's considered a junior specialist, which is kind of like a junior researcher," he said. The man is not presently in custody.

People living near the man's apartment at 418 Russell Park reported noticing some unusual smells emanating from that residence. A homemade air vent had been installed in a window of the apartment, located on the ground floor of the unit.